Quark, yogurt and vinai­grettes line Joachim Müller’s path as he walks through the high-bay ware­house of Elsdorfer Molk­erei und Feinkost GmbH, located 70 kilo­me­ters south­west of Hamburg. The building was constructed in 2011, and stores the company’s finished dairy prod­ucts on an impres­sive 4,500 pallets at a constant temper­a­ture of 5 degrees Celsius. Müller is the tech­nical director there. “We store perish­able goods here. That means that oper­a­tional reli­a­bility is very impor­tant to us. The ware­house must always be kept at a suit­able temper­a­ture, and there must not be any major fail­ures,” he says.

Room for improve­ment?

The previous venti­lation system completed this task reli­ably. Four large, direct drive fans each gener­ated an air flow of 62,500 m³/h while consuming 23 kW in power. This meant that the 1,000-square-meter building was always at a suit­able temper­a­ture. But at the begin­ning of this year, the energy manage­ment system was due for certi­fi­ca­tion according to DIN EN ISO 50001. The energy team at Elsdorfer is always looking out for the poten­tial for savings, but the venti­lation system was a sticking point for them. “Of course, the system is a major consumer, as it runs throughout the entire year.

The fans run for 24 hours, seven days a week,” says Müller. But at first, the parties involved were skep­tical as to whether replacing the fans would actu­ally bring about the desired energy savings. “The system was only nine years old, we couldn’t imagine that the tech­nology had devel­oped so much in that time frame,” says the tech­nical director.

From one to four

However, the company decided to try it out. After a consul­ta­tion with Dieter Hilde­brandt from Breuell & Hilgen­feldt GmbH, the deci­sion was made to replace one of the four fans first. Müller recalls: “To begin with, we wanted to see whether we could actu­ally make the antic­i­pated energy savings. For reasons of oper­a­tional reli­a­bility, we can only ever convert one venti­lation compo­nent at a time anyway, as the high-bay ware­house still has to be cooled in the mean­time.” With the aims of maxi­mizing reli­a­bility, improving air perfor­mance, and reducing the noise level, Dieter and his team devel­oped a FanGrid-based concept. This means that multiple fans are screwed into one wall. In the case of Elsdorfer Molk­erei, four RadiPac EC centrifugal fans were to replace the first of the four large fans.

In Elsdorfer Molk­erei und Feinkost GmbH’s high-bay ware­house, finished dairy prod­ucts are stored on up to 4,500 pallets. (Foto: Jan Hosan | Fotogloria)

The new venti­lation system with a total of 16 RadiPac EC fans ensures that the prod­ucts remain fresh at a constant 5 degrees Celsius. (Foto: Jan Hosan | Fotogloria)

To manage this, it required some help from another large vehicle first. Dieter reports: “We used a 40-meter-long, 110-ton car crane to shift the first of the large old fans, which were stored outside the ware­house in system containers.” Compared with that, installing the FanGrid was much easier. The conve­nient size of the fan cubes meant that two installers were able to bring them into the container and screw them to a wall. They were also quick to connect to the system thanks to plug and play. This was an obvious advan­tage. After five days of removal and instal­la­tion work, the FanGrid entered into service, boasting a power consump­tion of 17.8 kW, an air flow rate of up to 75,000 m^³/h, and a maximum pres­sure build-up of 900 Pa.

“As four fans now work together in one unit, we have improved our oper­a­tional reli­a­bility. If one fails, the other three will take over and keep the air volume constant.”

Joachim Müller, Tech­nical Director at Elsdorfer Molk­erei und Feinkost GmbH

A worth­while invest­ment

After the first fan had been in use for three months, one thing became clear to Joachim Müller and the team: the invest­ment was worth­while. Elsdorfer saved around 10,000 euros in energy costs, just by replacing the first fan. “We were honestly surprised that we could save that much energy as a result. We weren’t expecting that,” says Müller.

The FanGrid provided other bene­fits along­side its energy costs: “As four fans now work together in one unit, we have improved our oper­a­tional reli­a­bility. Thanks to the redun­dant design, it won’t matter if one fails, as the other three will take over and keep the air volume constant,” explains Müller. This is the key point for a ware­house with pallets full of perish­able goods.

For a ware­house with pallets full of perish­able goods, oper­a­tional safety is a key issue. (Photo: Jan Hosan | Fotogloria)

He also notes the advan­tages when performing repairs on the venti­lation system. It will not be essen­tial to carry them out quickly. In fact, the repair personnel can take their time. Another posi­tive side effect is also a lower noise level. The replace­ment has decreased this by around 12 dB(A): “We are located in a mixed area, with busi­nesses along­side resi­den­tial prop­er­ties. So noise emis­sion is also impor­tant here,” says Müller. “And since the project went so smoothly and simply, we agreed that we should also replace the other three venti­lation units with FanGrids.”

The four fan walls, made up of a total of 16 RadiPac EC centrifugal fans, have now been in oper­a­tion since May 2020, keeping the yogurt, quark and other prod­ucts cool as per require­ments. While the old fans required a power output of 78 percent, the FanGrids achieve the same air flow at 50 percent. As a result, Elsdorfer makes two sets of savings – around 47,000 euros per year in energy costs, and 100 metric tons in CO₂ emis­sions.